Microplasma Stamps - An Atmospheric-Pressure Plasma Source for the Area-Selective Modification of Surfaces

The patterned treatment of surfaces is of growing interest for a large range of applications in the fields of life sciences and polymer electronics. Microplasma stamps are based on the principle of dielectric barrier discharges and represent a powerful tool for the area-selective modification of various surfaces by the use of atmospheric pressure microplasmas, the so called plasma printing. This process integrates the surface modification and lateral microstructuring within one process step.

In the present work two different microplasma stamp concepts and their processing are described. In contrast to previous attempts microplasma stamps use a patterned dielectric barrier made of polydimethylsiloxane, which enables a good adjustment to wavy, corrugated and rough surfaces. The microplasma is generated in cavities which are formed temporarily by compressing the substrate to be treated area-selectively and a so-called plasma stamp. Thus, a well controlled spatial extension of the plasma is assured. For the generation of the structured PDMS dielectric barrier an improved method for the double-sided moulding of PDMS has been developed as well as a method for the fabrication of flexible master structures made of the negative working SU-8 photoresist.